mills



3 SheetsSheet 1.

F. E. MILLS. BEAGTING ROTARY STEAM ENGINE.

No. 107,078. Patented Sept! 6, 1870.

m: NORRIS PETERS co. PHOTO-LUNG. WASHINGTON. a. c.

3 She etsSheet 2.

1-. E. MILLS. REAGTING ROTARY STEAM ENGINE.

No; 107,078. Patented Sept.- 6, 1870.

F. E. MILLS. REAGTING ROTARY STEAM ENGINE.

No. 107,078. Patented Sept. 6, 1870.

I a o 6 R1 I E O0 coqo 0 one e 000 (Halted smu FRANoIs .n'. MILLS, OF SAN FRANCISCO, CALIFORNIA.

Letters Patent No. 107,078, datellseptember 6, 1870 antedated August 26, 1870.

REACTION ROTARY STEAM-ENGINE.

The Schedule referred to in these Letters Patent and making part or the same To all whom it may concern:

- Be it known that I, FRANCIS E. Mums, of the city and county of San Francisco in the State of California, have invented anew and useful Improvement in Reaction Engines, driven by steam orother elastic gas; and I do hereby declare that the'following is a full and exact description thereof, reference being bad to the accompanying drawing and to the letters of reference; marked thereon.

The nature of my invention consists- First, in providing reaction-wheels, driven by a current of steam or other elastic gas issuing against the atmosphere, with two broad expan'sion chambers, in

of an eiiicicnt resisting medium for the steam to act against, by inclosing the working-wheel in a drum or case, furnished with an adjustable gate 01" port, through which the expanded steam inside is allowed to escapenofiustcr than it is driven out by a pressure a little exceeding that of the atmosphere.

Third, giving such a direction to the current of hot steam, relative-to the head of the chamber, as to render eiTcc-tive whatever force there may he in its impact.

Principles and llfode of Operation.

-In all reactionsteam-wheels known to me, thehot steam leaves the wheelby spouting, with great velocity, againstt-heexternal atmosphere, throughtwo or more small orifices or tubes Now, if we suppose the hot steam issuing from the orilice to have apressnre of forty-five pouuds'to the square inch, the atmosphere being incapable of offer ing a resistance exceeding fifteen pounds, two-thirds otlthe force of thestcam' is entirely wasted in boring unrcsistc'd through the atmosphere, and, in order to render effective the remaining third, the wheelm'ust be driven with suchvclocity, approaching that of the issuing jet," as tountit the engine for most work; whcrcus, if the dense steam, on issuing from the orilice or throat, wcre permitted to expand laterally in thc'broad chambers DD while still confined to the wheel, untilits pressure should but little exceed that in the plane of the line X X, ti". 1.

of the atn'iosphere, and then in its exit blow against a broad transverse section of the external air, and react against a corresponding broad area of the chamber-head, nearly the whole power' of the steam would be rendered effective in the propdlsion of the wheel, audits movement could be made slow, as desired, by simply increasing the transverse area of the chambers relative to the throats. This presupposes, however, that the force of the steam is .not impaired by contact with the external air, before it hasdone its- 7 work. But, the condensation of the steam by such contact produces a constant partial vacuum between the issuing steam and the resisting atmosphere, which greatly abates the elastic energy of the former, and the effective resistanceof the latter; and it is to avoid this crippling efiect of driving the steam directly against the air, that I substitute a resisting medium of steam for that of the atmosphere. This I do by enclosing the working-wheel in a. steamtight drum, with an adjustable escape-port, so gauged as to keep the samealways full of the expanded steam, exerting a resisting pressure equal to one atmosphere.

The working-steam, then, expanding in the chamhers, is resisted by the elastic pressure oi the steam iuthe'drum, and reacting against the broad head of the chambers, drives the wheel in the opposite direction. Thus I'have steam working expansively against steam ulidernearly the same conditions as in the. modern piston engine, without its great cost and complica'i-tion, and, I think, without its percentage of wast Mode of Construction,

The general form of the invention and of all its parts will be apparent from the accompanying draw ing, which is a part of this specification, and in which- Figure 1 is an inside view of the casting, making one-half of the wheel vertical sctiom-cut at right angles with the shaft.

Figure 2 is a skeleton view of the wheel without the shaft.

Figure3 is a vertical sectionof the wheel andpresslue-drum, in position, the wheel being taken Figure 4 is a perspective elevation of the wheel resting on its hearings in the lower half of the pressure-drum, the upper half of the drum being removed, as shown at fig. 5. v

Figure 6 is a perspective elevation of the engine, with the drum closed'and ready for work.-

Figure 7 is a detail view, showing the gauge valve.

Figure'S is a view like ti". 1, showing alternative form of thegnide-arms, for a wheel of slow motion, the throats being at the center.

A'is the shalt oi the wheel, hollow at the port end.

.B, the hollow radial arms, leading from the center to the threats.

C, the throats, through which the hot steam enters the expansion chambers.

1), the expansion chambers, h the hen-(halal m the month of chambers.

E, the pressure-drum, inelosing the chambers.

F, the adjustable escape port, regulating the escape and pressure of thesteam in the drum.

G, the gauge-valve. regulating the area of the open: iug in the port.

H, the indicator-valve, to lift on the pressure exceeding the proper limit.

I, the air-valve, opening inside the'drum, to pre vent collapse.

K, the water-cock, to draw off the water condensing insde the drum.

L, tne waste-pipe, conveying ofi the escaped steam to heatthe t'eed-w'ater.

M, the main steam-pipe, leading from the boiler to the center of wheel.

N, thcthmtt-le-valve, ,operatcd by a governor or otherwise.

0, the 0CC6l'ltl'lC,. to drive the feed-pump.

Similar. letters of reference indicate like parts.

Thestea-m is admitted in one end of the hollow rhat't A, and conducted by the two opposite hollow arms or channels B to the two throats 0. These threats are simplya narrowing down of the steampassages in the arms to such small dimensions that only somuch steam can pass through them under a given pressure from the boiler, as vit is desired to use andthe absolute area of the throats will depend upon what power the engine is designed to yield, and the pressure of steam to be used.

The size ot'the'throats will be, of course, inversely as the pressure ofsteam,-and directly-as the power required.

These throats, respectively, open into the head of the expansion chambers D, the general form and position of which are shown in figs. 1, 2, 3, and 4, in 'the accompanying drawing.

On the size of these chambers, in their transverse section, depends the power with which :the wheel will move, as well as its'velocity, under a given pressure and quantity of steam, the power being directly,

and the velocity inversely to the area of their crosssection at the widest point; preciselywhat proportions should exist between the areas of the Cllttll'll'lfifhead and throat, in order to yield the best cfl'ect, will depend 'mainly on .the velocity it is intended to give the wheel, and the amount of load who moved.

With the escape-port properly gauged, I think I can calculate on an effective reacting resistance of at least ten pounds. per square inch of chamber-head, and something for the direct impulse of'the hot steam as it rushes lrom the throats; for it will be seen that 1 give the head of the chamber, h, such an angle rel: ative to the radial arms B that wl'iatcvcr force there may be in such impact is ma'de efi'ective in the propulsion ot'the wheel.

If desired, the threats maybe made au ustable by fixing a sliding key in the back of each, in order that the. proportions between the areas" ot the throats and chambers may he varied-to suit different requirements ot'the same engine.

I make theentire wheel, inchuling the radial arms B, thethroats O, and the expansion chambers I), of cast iron, casting it in two correspomling parts, out transversely to the axis, the walls of the steam passages being'raised or projected from the side plates in the form of flanges, as shown infig. 1-.

The edges of these flanges having been brought'to one true plane, t..e-t\vo correspondingparts are bolted strongly togethenand made steam-tight.

Pressure Drum.

in most cases where steam is used as the motor, 1 make the pressure-drum in the form of a separate case, inclosing the entire wheel, the shaft of. the wheel passing through it, as shown at E E,,figs.,3,' 4, and 6. It is cut-horizontally, in two equal parts, thelower half being made strong and-heavy, sustains the horizontal shaft of the wheel, the upper-half may be made of thick sheet iron, and should be covered with felt.

This upper half may be hung on strong hinges, so as to be readily opened and closed, or it may be made to lift off entirely, and when closed fastened with books or'clamps.

The correspondingedges of the two parts should be linedwith soft leather, or other packing, to make the joint .tight.

In the top of this drum I cut an opening, large enough to allow all the steam which may be drii'en through the throats of the wheel to escape under a pressure slightly exceeding' one atmosphere,jallowance' being made for leakage, and the condensation and liquil'aetion of a portion of the steam by cooling, &G..

To thiscscapc-port I attach a valve, by which its size may be'always so adjusted and limitedthat no air can enter to condense the stealn, and theiste am be allowed to escape no faster than just sufficient to prevent thepressure. inside from mnclrexcecding that assigned limit.

If the pressure'ot' hot. steam passing through the throats of the wheel were always unform, and the temperature of the atmosphere surrounding the drum always. uniform, the size of this escape-port could be calculated, and then remain fixed; but oWing-to-t-he variations in. these conditions, it should be made adjustable, for if too small steam will accumulate in the drum, and escape attoo high a pressure, occasioning a loss of power as well as endangering the bursting of the drum; if too large,- the vacuum of condensation willdiminish the elastic'resistanec inside.

This escape-port may be adjusted. by hand,-on the state of the pressure being made known by an indicator-valve, H, and the ail-waive I, but it is-better topreventalcollapse ot' the drum from the condensatiou, when the engine is stopped, as well 'as to assist in ascertaiuing the state otthe pressure inside.

1n the bottom of-the pressure-drum I nnike ,an

. aperture, closed with .a stop-cock, K, for drawing off the water which may collect in the drum, from the condensation of the steam.

The expanded steam, escaping through the port, may .beconducted o tt' through the waste pipe L,

'fig. 6, andused to heat the feed-water for the boiler.

In the main steam pipe, in, leading from the boiler to the center of the wheel. I construct a valve, N, similar-to the throttle-valve of the ordinary pistonengine, to regulate the supply ofsteam to the wheel,

and equalize its movement, this valve being operated by the ordinary governor, or its equivalent.

Alternative Form of th'c Arms and Throats.

In cases where the motion of the wheel is desired to be quite slow, I place the throats at or near the center of the wheel, and allow the arms, while still retaining their radial position, to open from the throats into the reaction heads of the chambers, substantially in the form shown at B, fig, 8.

Claims.

What I claim as my invention, and desire to secure by Letters Patent, is-- 1. In a reaction-wheel, driven by steam or other elastic gas, rushing against the atmosphere or "other surrounding medium, the expansion-chambers D D, in combination with the throats O, substantially as and for the purpose described.

2. In combination with a reaction-wheel, driven by steam or other elastic gas, the pressure-drum E E, with the adjust-able escape-port F, and the watercock K, substantially as and for the purposes de scribed.

- FRANCIS E. MILLS. Witnesses: LOUIS RAOUL THIESSEN, HENRY KLEINE. 

